Reversible pressure fluid actuated vane motor

ABSTRACT

A REVERSIBLE PRESSURE FLUID ACTUATED VANE MOTOR HAS A REVERSING VALVE AND A CYLINDER WITH DUAL OUTLET PORTS. EXHAUST FROM THE OUTLET PORTS PASSES VIA A CAVITY IN THE MOTOR HOUSING TO THE SURROUNDING ATMOSPHERE WITHOUT PASSING THE REVERSING VALVE. VALVE MEANS AND COOPERATING VALVE CLOSING MEANS ARE PROVIDED IN THE CAVITY FOR CLOSING THE ONE OF SAID OUTLET PORTS OFFERING DURING ROTATION IN THE RESPECTIVE ROTATIONAL DIRECTIONS THE FIRST PRESSURE FLUID CONNECTION BETWEEN THE MOTOR CYLINDER AND THE CAVITY.

Feb. 27, 1973 G. BERGER ET AL 3,

REVERSIBLE PHLSSURE FLUID ACTUATED VANE MOTOR Filed Dec. 22, 1970 2 Sheets-Sheet 1 REVERSIBLE PRESSURE FLUID ACTUATBD VANE MOTOR Filed Dec. 22, 1970 Feb. 27, 1973 K. G. BERGER ET AL 2 Sheets-Sheet 2 I 3 I 7 I 3 4 0 x IV! I l United States Patent 3,718,410 REVERSIBLE PRESSURE FLUID ACTUATED VANE MOTOR Karl Gustav Berger, Nacka, and Gustaf Harry Fernstrom,

Klinten, Sweden, assignors to Atlas Copco Aktiebolag,

Nacka, Sweden Filed Dec. 22, 1970, Ser. No. 100,606 Claims priority, application Sweden, Dec. 31, 1969,

18,136/ 69 Int. Cl. F01c 21/12; F 036 3/00; F04c 29/08 U.S. Cl. 418- 8 Claims ABSTRACT OF THE DISCLOSURE The invention relates generally to pressure fluid actuated vane motors and more particularly to reversible vane motors including a reversing valve, a motor cylinder, and a pair of outlet ports in the cylinder each having a cooperating valve means adapted to alternately close the one of the outlet ports offering during rotation in the respective rotational directions the first exhaust occasion from said cylinder. in such vane motors application of the valve means is directed towards gaining in both rotational directions of the motor the same maximum power output as attainable by a corresponding non-reversible motor.

Hitherto (US. Pat. 2,261,204, British Pat. 546,372) such valve means have been disposed usually under preliminary spring load in the pressure fluid inlet passages of the motor and the necessary full closing load was applied by live pressure fluid alternately entering the inlet passages under the control of the reversing valve. The disadvantage of this arrangement is that expanded pressure fluid expelled from the main outlet ports must pass the revers ing valve. In connection with hand sustained tools the reversing valve by practical reasons has to be made of relatively small size, and therefore there is created a considerable loss of power by throttling in the under-dimensioned reversing valve during exhaust to the surrounding atmosphere. Thus in a motor output of for example three horse powers such power losses may attain the order of magnitude of half a horsepower. The counter pressure maintained by the preliminary spring load of the valve means also contributes to the power losses. Accordingly it is an object of the invention to effectively reduce or to eliminate the power losses here in question.

For the above and other purposes there is according to the invention provided a reversible pressure fluid actuated vane motor comprising a housing, a motor cylinder in said housing, a vane rotor rotatably mounted in said motor cylinder, a supply passage in said housing for supplying pressure fluid to said motor, inlet passage means in said housing connected to said motor cylinder, at twoposition reversing valve in said housing between said supply passage and said inlet passage means for derfining the rotational direction of said vane rotor in accordance with the position of said reversing valve, a pair of angularly spaced outlet port means in said motor cylinder, a cavity in said housing for receiving the exhaust from said outlet port means, a connection between said cavity and the 3,718,41 Patented Feb. 27, 1973 surrounding atmosphere separate from said reversing valve, valve means in said cavity associated with each outlet port means for opening and closing said port means relative to said cavity, and closing means in said cavity engageable with said valve means for alternately closing the one of said valve means ofiering during rotation in the respective rotational directions the first exhaust connection between said cylinder and said cavity.

The above and other purposes of the invention will become obvious from the following description and from the accompanying drawings in which two embodiments of the invention are illustrated by Way of example. It should be understood that these embodiments are only illustrative of the invention and that various modifications thereof may be made within the scope of the claims following hereinafter. I

In the drawings, FIG. 1 shows a longitudinal section through a vane motor according to the invention seen substantially on the line 1-1 in FIG. 3. FIG. 2 is a cross section on the line 2-2 in FIG. 1. FIG. 3 is a cross section on the line 33 in FIG. 1. FIG. 4 is a cross section corresponding to FIG. 3 through a modified embodiment of the invention. FIG. 5 is a fragmentary view seen on the line 5-5 in FIG. 4.

The vane motor comprises a housing 10 which by screws, not shown, is clamped between a front cover 11 and a rear cover 12 and includes an inner cavity 16 with cylindrical end bores 13. In the end bores 13 are inserted journalling bodies, a front body 14 and a rear body 15", carrying ball bearings 17 in which a vane rotor 18 is journalled by way of a rear journal 19 and a front drive shaft 20 concentrically with the end bores 13. The vane rotor 18 is surrounded by a motor cylinder 21 fixed eccentrically with respect to the end bores 13 in the cavity 16 and having a pair of overhead inlet jackets 22, 23 connected thereto. Vanes 25 which are radially movably guided within slits 24 in the rotor 18, slide in a well known manner against the inside of motor cylinder 21. Pressure fluid can pass from the respective inlet jacket 22, 23 into the cylinder 21 via inlet openings 26 and 27, respectively. The motor cylinder 21 is provided with two angularly spaced alternative main outlet ports 28, 29 each including a number of bores or axial slots. The cavity 16 around the intermediate portion of the cylinder 21 and around the inlet jackets 22, 23 thereof is in direct communication with the surrounding atmosphere via bores 31. In association with outlet bores there may if necessary be arranged some suitable conventional exhaust sound muflling device, not shown.

The cavity 16 has at the lower port-ion thereof a pair of pockets 32, 33 in which are received rubber bladders 34, 35 providing inflatable and deflatable expausible chamber devices. Between the pockets 32, 33 there projects upwardly a saddle shaped bead 44 into the cavity 16 providing a support for a two-position valve means 30 for alternate closing of the main outlet ports 28, 29. The valve means 30 is designed as a rocker with rocker arms 36, 37, is journalled on the bead 44, and is preferably made of relatively rigid rubber material. Against the one rooker arm 36 the rubber bladder 34 may be applied by way of expansion to act as a closing member for the outlet port 28, while against the other rociker arm 37 the rubber bladder 35 may be similarly applied by way of expansion for closing the outlet port 29.

Pressure fluid such as compressed air is supplied to the housing 10 via a hose 39 which is connected to a valve case 40. In the valve case 40 is arranged a two-position reversing valve 41, in the instant example designed as a flat slide adapted for manual actuation by means of a push rod 42 and adjustable to take two end positions. In the end position illustrated in FIG. 3 the hose 39 is connected via the guide passage 38 of the reversing valve 41 to an inlet passage 43 formed partly in the housing 10 and partly in the rear journalling body 15. Via the journalling body 15 the inlet passage 43 is in communication with the interior of the jacket 22. Simultaneously the reversing valve 41 by an inner recess 45 connects an inlet passage 46, likewise formed partly in the housing 10 and partly in the rear journalling body 15, with an axial passage 47 in the housing 10. Hhe axial passage 47 is connected to the cavity 16 and is thus via the bores 31 thereof in direct communication with the atmosphere. Via the journalling body 15 the inlet passage 46 is in communication with the interior of the inlet jacket 23.

The inlet passage 43 is through a passage 50 in the housing 10 in connection with the expansion chamber or interior of the rubber bladder 34 while the inlet passage 46 through a similar passage 51 is connected to the expansion chamber or interior of the rubber bladder 35.

It is obvious that by movement of the push rod 42 to the left in FIG. 3 the reversing valve 41 can be shifted to an opposite end position in the guiding passage 38 thereof, at which instant the hose 39 is connected directly to the inlet passage 46 while the inlet passage 43 via the cavity 45 in the reversing valve 41 is connected to the axial bore 47 and thence via the cavity 16 and the bores 31 to the surrounding atmosphere.

Let it be supposed that the vane motor works with the reversing valve 41 in the position depicted n FIG. 3 Pressure fluid enters from the hose 39 into the inlet passage 43 and also via the bore 50 into the rubber bladder 34. The latter expands and rocks upward the rocker arm 36 to close the outlet port 28 nearest to the inlet passage 26 simultaneously with the inlet 26 passage being supplied with pressure fluid via the inlet passage 43 and the inlet jacket 22. Thus the vane rotor 18 will be rotated. The inlet passage 46 is relieved to the surrounding atmosphere via the recess 45 of the reversing valve 41, the axial bore 47, the cavity 16, and the bores 31. The rubber bladder will be likewise relieved via the bore 51 and deflected or contracted and thus the rocking arm 37 is kept open and the outlet port 29 remains open with respect to the cavity 16 and the surrounding atmosphere for purposes of exhausting the working fluid with a minimum of throttling losses. During rotation in the direction defined by pressure fluid supply to the inlet passage 43 the first occasion for exhaust from the cylinder 21 would be offered by the outlet port 28 when passed by the vanes 25. However, since outlet port 28 is kept closed and inactive, the vanes will rotate on drivingly over an extended drive angle until actual exhaust takes place when the vanes 25 pass the active outlet port 29. The extended drive angle results in increased output of power. When the vanes 25 have passed the outlet port 29 there is usually performed an expelling of residual air via the inlet openng 27 and the inlet jacket 23 to the relieved inlet passage 46. The exhausting of residual air via the reversing valve 41 affects an insignificant quantity of air and thus the throttling losses are negligible.

When the reversing valve 41 is switched to its opposite end position, not shown, the rotational directon will be reversed since live pressure fluid now will be supplied to the inlet passage 46. The bladder 35 will be inflated via the bore 51 to switch rocker valve 30 and close outlet port 29. Simultaneously inlet passage 43 is relieved to the atmosphere and the rubber bladder 34 likewise relieved via the passage 50. With the outlet port 29 inactive and outlet port 28 active the now oppositely rotating vanes 25 will still cover an extended drive angle. By virtue of the symmetric arrangement of the motor, the power output will be unaltered and unaffected by the chosen rotational direction.

In the embodiment of FIGS. 4, 5 the valve 30 with the rocker arms 36, 37 is shown unaltered but is actuated by closing members provided by abutments settable against the rocker arms 36, 37. By way of example these abutments are formed as parts of eccentrics 52, 53 wherein the abutments are plane surfaces 54, 55. The surfaces 54, 55 are alternately movable against the rocker arms 36, 37 and serve to arrest the eccentrics 52, 53 in two alternative adjusted positions and to cooperate lockingly with the rear surfaces of the rocker arms 36, 37. The adjustment is had as a result of actuation of an axle 56 on which the eccentrics 62, 63 are fixed. The axle 56 is turnably journalled in the housing 10 and can be adjusted to the desired angular position by means of a knob 57 outside of the housing 10.

What we claim is:

1. A reversible pressure fluid actuated vane motor comprising a housing, a motor cylinder in said housing, a vane rotor rotatably mounted in said motor cylinder, a supply passage in said housing for supplying pressure fluid to said motor, inlet passage means in said housing connected to said motor cylinder, a two-position reversing valve in said housing between said supply passage and said inlet passage means for defining the rotational direction of said vane rotor in accordance with the position of said reversing valve, a pair of angularly spaced oulet port means in said motor cylinder, an exhaust cavity in said housing for receiving the exhaust from said outlet port means, a connection between said exhaust cavity and the surrounding atmosphere separate from said reversing valve so that substantially all of the exhaust fluid from said outlet port means is passed to the surrounding atmosphere without passing through said reversing valve means in said exhaust cavity associated with each outlet port means for selectively opening and closing said outlet port means relative to said exhaust cavity, and closing means in said exhaust cavity engageable with said valve means for selectively and alternately closing the valve means which offers during rotation in the respective rotational directions the first exhaust connection between said cylinder and said exhaust cavity.

2. A vane motor according to claim 1 in which said valve means includes a rocker pivotally mounted on said cylinder to selectively and alternately open said outlet port means.

3. A vane motor according to claim 2 in which said closing means are a pair of expansible chamber devices selectively inflatable against the opposed ends of said rocker, and means responsive to the position of said reversing valve for selectively and alternatively inflating said devices.

4. A vane motor according to claim 2 in which said closing means comprises eccentrics selectively applicable against the opposed ends of said rocker, and a shaft turnably mounted in said housing and carrying said eccentrics for selectively and alternately applying them against said ends of said rocker in response to turning of said shaft.

5. A reversible pressure fluid actuated vane motor comprising a housing, a motor cylinder in said housing, a vane motor rotably mounted in said motor cyllinder, a supply passage in said housing for supplying pressure fluid to said motor, a pair of inlet passages in said housing connected to said motor cylinder for rotating said vane rotor bidirectionally with the rotational direction depending on whichever of said inlet passages is being supplied with pressure fluid, a two-position reversing valve in said housing between said supply passage and said inlet passages for alternately supplying said inlet passages with pressure fluid, passage means in said reversing valve for simultaneously exhausting the one of said inlet passages not supplied with pressure fluid, a pair of angularly spaced outlet port means in said 'motor cylinder, an exhaust cavity in said housing for receiving the exhaust from said outlet port means, a connection between said exhaust cavity and the surrounding atmosphere separate from said reversing valve so that substantially all of the exhaust fluid from said outlet port means is passed to the surrounding atmosphere without passing through said reversing valve means, valve means associated with each outlet port means for opening and closing said port means relative to said exhaust cavity, and closing means in said exhaust cavity engageable with said valve means for selectively and alternately closing the one of said outlet port means nearest to the inlet passage actually supplied with compressed air.

6. A vane motor according to claim 5 in which said valve means includes a rocker pivotally mounted on said cylinder to selectively and alternately close and open said outlet port means.

7. A vane motor according to claim 5 in which said closing means comprises a pair of expansible chamber devices selectively inflatable against said valve means, and passage mens connecting each inlet passage with one of said devices for selectively and alternately inflating and deflating said devices.

8. A vane motor according to claim 6 in which said expansible chamber devices are rubber bladders.

References Cited UNITED STATES PATENTS 409,800 8/1889 Owen 418-239 1,068,378 7/1913 Wold 4l8-239 224,146 2/1880 Chathcart 418266 2,715,889 8/1955 Sturrock 418-159 FOREIGN PATENTS 395,420 5/1924 Germany 418-270 982,180 1/1951 France 418-270 CARLTON R. CROYLE, Primary Examiner J. J. VRABLIK, Assistant Examiner US. Cl. X.R. 418-159, 270

UNITED STATES PATENT OFFICE CERTIFICATE OF CGRRECTION Patent No. 3 718 ,410 Dated February 27 1973 Inventor(s) KARL GUSTAV B ERGER et al It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4 line 40 (CElaim 2) after "alternately" insert close and-1.

' i Column 4 line 56 (Cilaim 5 the word "motor" should be -rotor-'-- i Column" 5., 'line 17 (Cilaim 8) the numeral "'6" should be --7-.

Signed and sealed this 18th day of December 1973.

(SEAL) Attest:

RENE D. TEGT MEYER Acting Commissioner of Patents EDWARD M.FLETCHER,JR. Attesting Officer uscoMM-Dc borne-ps9 U.S. GOVERNMENT PRINTING OFFICE I 1969 O-3GG-33L FORM PO-1050(10-69) 

